TY - JOUR
T1 - The tumor necrosis factor type 2 receptor plays a protective role in tumor necrosis factor-α-induced bone resorption lacunae on mouse calvariae
AU - Nagano, Kenichi
AU - Alles, Neil
AU - Mian, Anower Hussain
AU - Shimoda, Asako
AU - Morimoto, Nobuyuki
AU - Tamura, Yukihiko
AU - Shimokawa, Hitoyata
AU - Akiyoshi, Kazunari
AU - Ohya, Keiichi
AU - Aoki, Kazuhiro
PY - 2011/11
Y1 - 2011/11
N2 - Tumor necrosis factor (TNF)-α exerts its biological function via TNF type 1 and type 2 receptors (TNFR1 and TNFR2). We have previously reported that bone resorption induced by lipopolysaccharide (LPS) in TNFR2-deficient mice is accelerated compared to that in wild-type (WT) mice. Although these results suggested that TNFR2 might have a protective role in bone resorption, we could not exclude the possibility that TNFR2 has no role in bone resorption. To clarify the role of TNFR2, we developed a TNF-α-induced bone resorption model using cholesterol-bearing pullulan nanogel as a TNF-α carrier to minimize the influence of inflammatory cytokines other than TNF-α. Injections of human TNF-α (hTNF), an agonist of mouse TNFR1, stimulated bone resorption lacunae on the calvariae in WT mice, but mouse TNF-α (mTNF), an agonist of both mouse TNFR1 and TNFR2, could not. To eliminate the possibility that the TNFR1 agonistic effects of hTNF were stronger than those of mTNF, we used the same model in TNFR2-deficient mice. Injection of mTNF resulted in clear bone resorption lacunae to the same extent observed after using hTNF in the TNFR2-deficient mice. Histomorphometric analysis of osteoclast number supported the observed changes in bone resorption lacunae. These data suggest that TNFR2 has a protective role in TNF-α-induced bone resorption.
AB - Tumor necrosis factor (TNF)-α exerts its biological function via TNF type 1 and type 2 receptors (TNFR1 and TNFR2). We have previously reported that bone resorption induced by lipopolysaccharide (LPS) in TNFR2-deficient mice is accelerated compared to that in wild-type (WT) mice. Although these results suggested that TNFR2 might have a protective role in bone resorption, we could not exclude the possibility that TNFR2 has no role in bone resorption. To clarify the role of TNFR2, we developed a TNF-α-induced bone resorption model using cholesterol-bearing pullulan nanogel as a TNF-α carrier to minimize the influence of inflammatory cytokines other than TNF-α. Injections of human TNF-α (hTNF), an agonist of mouse TNFR1, stimulated bone resorption lacunae on the calvariae in WT mice, but mouse TNF-α (mTNF), an agonist of both mouse TNFR1 and TNFR2, could not. To eliminate the possibility that the TNFR1 agonistic effects of hTNF were stronger than those of mTNF, we used the same model in TNFR2-deficient mice. Injection of mTNF resulted in clear bone resorption lacunae to the same extent observed after using hTNF in the TNFR2-deficient mice. Histomorphometric analysis of osteoclast number supported the observed changes in bone resorption lacunae. These data suggest that TNFR2 has a protective role in TNF-α-induced bone resorption.
KW - Bone resorption lacunae
KW - Cholesterol-bearing pullulan
KW - Human TNF-α
KW - Mouse TNF-α
KW - TNF type 2 receptor
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U2 - 10.1007/s00774-011-0270-z
DO - 10.1007/s00774-011-0270-z
M3 - Article
C2 - 21626455
AN - SCOPUS:83055194715
VL - 29
SP - 671
EP - 681
JO - Journal of Bone and Mineral Metabolism
JF - Journal of Bone and Mineral Metabolism
SN - 0914-8779
IS - 6
ER -